Rush Skeletonweed

rushskeletonweed_sm_000A member of the Sunflower family, rush skeleton weed is a perennial which grows from 1 to 4 feet tall. Starting at the stem base for 4 to 6 inches, stems usually have downwardly bent coarse hairs with smooth stems above. The leaves are sharply toothed and form a basal rosette that wither as a flower stem develops. Flowering heads are scattered on branches, approximately ¾ inch in diameter, with 7 to 15 yellow, strap-shaped flowers. Flowering occurs from mid-July through frost. The stems and leaves have a milky latex inside.

Rush skeleton weed was introduced from Eurasia. It can be found on well-drained, light-textured soils along roadsides, in rangelands, grain fields and pastures. Soil disturbance aids establishment. Rush skeleton weed is difficult to control because of the extensive deep root system.

Rush skeleton is in Idaho. Residents of northwestern Colorado should be watching for this species.